Sign apparatus of this kind has been implemented with electrical illuminating means such as filament lamps, neon tubes and the like, for it to be readable at large distances, e.g. when it is erected at a relatively large height above the plan of view where the observer is. Apart from such illuminating means having a relatively short life they are also power-consuming.
Electrically driven filament lamps which may be illuminated and extinguished are customarily used for sign apparatus having jumping characters. Since these light sources have short life due to the repeated illumination and extinguishing there have been attempts to utilize light emitting diodes (LED's) for them. Primarily for reasons of expense, matrices have been used in such cases, placed one after the other with a predetermined number of LED's arranged within a given area. There are thus available rectangular matrices with 7.times.9 LED's, i.e. nine columns each having seven LED's. However, it has been found that such LED signs have poor illumination effect.